Without a 2M radio you wouldn't be able to hear or transmit on those frequencies. Basically what they are is different radio bands set aside on the 2M bandwidth that we transmit on. It goes through a repeater and the +/- with the corresponding number is a pulse tone to open up the repeater allowing them to work to retransmit what you are saying much farther than on simplex which is line of sight. With a repeater as long as your antenna can see the radio transmissions you can hear what being said and transmit which is what makes them so nice. A CB is purely line of sight with a low power band so they can obviously be problematic at times. Look at it similar to frequency hopping using a MBTTR to a very small extent as an example.
Minor thread jack here...but I wanted to springboard onto Celt's comments about ham radios, repeaters, and 2 meter transmitting.
Firstly...buy a Baofeng inexpensive 2 meter HT (ham lingo for "handy-talkie", aka hand held radio) so you can monitor trail comms and stay in the loop on SCCX runs. Believe me, the radio chatter within the first 100 yards of the recent Bradshaw Trail Xcursion was worth the trip alone! If you live in San Diego, visit Ham Radio Outlet to check out some of the inexpensive 2 meter options, or shop the Shame-a-zone for Baofengs here:
BaoFeng UV-5R HT Dual BandFor 25 dollars you get a great radio, and easy loop in to trail comms. When you get time, study for your ham license (easier than a driving test, and could save your life some day....35 questions, 70 percent is passing, need I say more??) and then you unlock the keys to the cool kids club.
Secondly...repeaters are unique to amatuer radio, wherein they essentially boost you transmitted signal from a high point (usually a mountain top) and then re-broadcast over a specific area of coverage. This process doubles or sometimes triples your transmission capabilities in distance...take that Children's Band!!!
I know CB is the easy option, but for the same price you would pay (actually less) for a full CB set up, you get crystal clear trail comms and a peek into the window of amateur radio. PLUS...when you get your license, you get a really cool federally issued call sign.
As you can tell, I am a strongly supportive advocate for ham/amateur radio licensing, and the hobby in general (pun intended, you'll get it when you check out the different classes of licensing
)
So consider this option, becuase you won't regret it.
We have 40+ hams in this "not a club/club,"
which started out with less than a half dozen.
Have fun, please feel free to PM me any questions you have, as I'm happy to help!!
John/Ghost65
...end Thread Jack.